Tried my hand at re-pointing yesterday, it is a hell of a lot more difficult than it looks. It's the usual story with a 100 year plus house. Went up the ladder to clean the brick work around the bay window with some hydrochloric acid stuff that I got in B&Q. Started scrubbing at the brickwork with a wire brush, and lumps of mortar started falling out. So I decided to mix some mortar up and plug the gaps. Firstly the mortar is almost white yet the other stuff is weathered to a greeny grey so it looks bad. Secondly mortaring the vertical joints is really difficult, on the horizontal you can put the mortar on the edge of the trowel and easily fill it in, on the vertical it's really difficult to get it in the gaps.
The mortar I have is that easipoint stuff, and I was using it without the pointing gun, because I haven't bought one yet, so maybe that is why.